Conjugated Metal-Based Coilable Materials: Synthesis, Characterization, Conformation and Function

The ubiquity and multifunctionality of the helical motif in nature has inspired researchers to strive for synthetic systems of increasing complexity, but the study of metal-based polymers with controllable helical sense remains in its infancy. This proposal concerns the design, preparation and characterization of coilable conjugated metallopolymers, and their application as helical architectures and functional materials. In contrast to static helical polymers, dynamic systems confer flexibility, responsiveness and potential tunability, thus rendering them more amenable to development of functionality. The synthesis of conjugated polymers featuring suitable metal-organic moieties and chiral sidearm substituents (including biological building blocks), that can organize into helical structures stabilized by non-covalent intrachain interactions, is proposed. The folded conformation, luminescence, amphiphilicity, and supramolecular organization of these stimuli-responsive metal-based polymers will be investigated. Fundamental issues, including elucidating the type and combination of chiral substituents required to achieve flexibility and dynamic behavior while preserving the ordered coiling (helicity), and probing the nature and cooperativity of intrachain interactions affecting the helical conformation, will be addressed. Significant preliminary results (including organized aggregation-assembly and in biological applications) have been obtained. The underlying aim is to develop metal-based helical structures with controllable, dynamic conformations and diverse characteristics (of functional groups, polarity/amphiphilicity, binding properties/reactivity), toward applications in molecular recognition, catalysis, and as bioinspired chiral materials.